OCaml Code: Attached are the instructions. Below is the code where the functions needs to be changed. Please make sure to read the instructions attached. Make sure to write test cases and test them in order to see if the code works. Make sure to give a screenshot of the code and the output of the test cases being tested. "ALBUM by ARTIST". Finally, computers should be "Public Computer". You may find theOCaML function string_of_int: int -> string helpful.Example Outputs# string_of_item (Book ("Types and Programming Languages", "Benjamin Pierce")) ;;- : string = "Types and Programming Languages by Benjamin Pierce"# string_of_item (Movie ("The Imitation Game", 2014)) ;;-: string = "The Imitation Game (2014)"#string_of_item Computer;;string = "Public Computer"2.2 string_of_entry checkout_entry -> stringThe second function you must implement converts checkout_entry to a string. An normal Itemshall be rendered just as the wrapped catalog_item would be. A new entry should be rendered as"(NEW) ENTRY", where ENTRY is the wrapped checkout_entry. A pair should be "ENTRY1and ENTRY2", where ENTRY1 and ENTRY2 are the items. In implementing this function, youmay wish to call the string_of_item function you previously wrote.Example Outputs#string_of_entry (Item (Book ("Types and Programming Languages", "Benjamin Pierce"))) ;;- string = "Types and Programming Languages by Benjamin Pierce"# string_of_entry (New (Item (Movie ("The Imitation Game", 2014)))) ;;- string "(NEW) The Imitation Game (2014)"2.3 daily_fine: checkout_entry -> floatThe third function you must implement computes the fines (in dollars) incurred for each day anitem is overdue. The fines are as follows:• Books: 0.25• Movie: 0.50• CD: 0.50• Computer: 0.00• New Items: Double the normal fine• Pair: The sum of the fines for each item2.4 total fine checkout list -> floatThe fourth function you will implement takes a list of checkout and returns the total fine for allitems. Remember, if the int option is None, the item is not overdue and thus no fines are due forthat item.You may find float_of_int: int -> float helpful in implementing this function. In this assignment you are asked to implement portions of the checkout system backend for theOakland, California Municipal Library (OCaML). You will be writing functions to handle calcu-lating fines for overdue items. Your implementations must adhere to a specified behavior and type(or signature). These functions will operate on a set of three nested data types representing thelibrary's records.The data types representing records are defined as follows:type catalog_item = Book of string * string | Movie of string * int |CD of string * string | Computertype checkout_entry = Item of catalog_item | New of checkout_entry |Pair of checkout_entry * checkout_entrytype checkout Checkout of checkout_entry * int optionThese definitions are also provided in the file library.ml which you can use as a basis for yourdevelopment.Note that constructor names must begin with a capital letter, and binding names must beginwith a lowercase letter (or an underscore).Here a catalog_item represents one physical item in the library. For a book, the parametersare the title and author. For a movie, the parameters are title and year. For a CD, the parametersare the album name and artist. Computer represents using a public computer, and thus has noarguments.Some items are new or can only be checked out as a pair with another item. A checkout_entryrepresents one checked out bundle. Finally, a checkout combines a checkout_entry with an integeroption representing the number of days overdue. If the option is None, the item is not overdue. Ifthe option is Some n, n is the number of days the item is overdue. You may assume n is alwayspositive.2 Function specifications2.1 string_of_item : catalog_item -> stringThe first function you will implement converts a catalog_item to a string. Books shall be renderedas "TITLE by AUTHOR". A movie shall be "TITLE (YEAR)". A CD shall be rendered as

In this question we have to implement the specific function specialist provided in the function…

Answered: OCaml Code: Attached are the…

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE